The pump on a 200/300 tdi can be adjusted to give 25 BHP extra . Proceed as follows.Stage one is to increase the turbo pressure ...you must shorten the waste gate rod by about 6 mm to raise the turbo pressure to 16 psi..easy on a 200 pig on a 300 ...mind you dont loose the circlip and loosen the locking nut first ...make a length of 1/2 in bar with a slot in the end to push the rod back into place ...essential on a 300. Use a gauge to measure the pressure ...T piece in pipe to injection pump...fuel pressure gauge is often the cheapest to buy ...plastic screen washer T is OK. ( the above adjustment alone will give no increase in performance)

Stage 2

remove the four screws from the power valve on top of the pump ( squarish plate with brass cover in centre ..big screwdriver very tight) The top of the plate will spring up...notice how far it rises on top of the spring.(say 7mm) Remove the cover. Then you will see a black diaphragm..if you want with tippex mark its position relative to the casing and then remove the diaphragm (lift edges and pull up) remove the spring underneath (do not move the throttle when the diaphragm is out !!) at the bottom of the cavity you will see a toothed wheel. You need to screw this down to reduce the lift in the top plate to about 3mm ( 7 - 4 =3 ) Wind it down with the edge of a screwdriver and then re fit everything to check the lift . Now examine the shaft on the diaphragm ...you will see an off centre cut out at the bottom ...re fit the diaphragm with the deepest part of the cut out towards the rear of the vehicle...this gives you max fuel. dont forget the spring and check you still have some lift in the top plate as you screw it down...thats it done .....If you do have some smoke then you have two choices ...increase the turbo pressure or reduce the fuel a little by rotating the diaphragm a little clock or anticlockwise ... I do not advise adjusting the screw under the brass cap or the main fuel adjuster at the rear ...you may get a tiny bit more but when you get smoke its a pain to know what to adjust ..adjust only the three items mentioned ...turbo pressure...diaphragm rotation and spring pressure...if you need any more information or diagrams just ask.this is not my right up i just borrowed it to get the best from this you are better fitting a bigger intercooler as wellthis is the link to the original site http://dividingcreekroverimports.com/technical_info_from_the_web

A word of warning though, if you have a heavy right foot and are running high boost in this way you are at risk of blowing your head gasket, I personally know two people that have done it, one with a dico 300 and one with a defender 300. you have been warned!